The invention relates to a device comprising a rotationally driven surgical instrument having a hand-held element provided with a mount rotatably installed therein for reception of interchangeable cutting and milling inserts, a driving motor for driving the mount receiving the tool inserts, a control unit for controlling the driving motor with means of setting the rotational speed and of preselecting the rotational speed range and direction of rotation, as well as a digital indicator for display of the rotational speed set in each case.